It is known to provide a rear vision system for a vehicle such as a motor vehicle. Typically, the rear vision system includes a pair of outside or exterior side rearview mirrors, one on both driver and passenger sides of the vehicle, and an inside or interior rearview mirror in an occupant compartment of the vehicle.
Such a rear vision system may be power operated to allow a driver to remotely and individually adjust the side and interior rearview mirrors without physically attending them. These mirrors are typically adjustable both vertically (up/down) and horizontally (left/right), using electric motors controlled by the driver via a mirror position switch.
Usually, a single mirror position switch assembly is used, which includes a joystick type switch for directing the two-directional movement of the motors as well as a left/right selector switch that switches between the two exterior side rearview mirrors so that they can be adjusted one at a time, independently of each other. The selector switch may also include a locked position so that movement of the joystick does not activate either of the mirror motors.
On vehicles provided with memory positioning, the mirrors can be automatically moved by suitable vehicle circuitry to a preset position established by the driver. Such circuitry can be implemented using position sensors on the mirrors to determine the instantaneous position of the mirrors in both the horizontal and vertical directions. These types of mirror positioning circuits are well known.
It is also known to automatically adjust a rear vision system for a vehicle. One example of such a system is disclosed in U.S. Pat. No. 6,840,637 to Wang. In this patent, adjustments by a vehicle operator to a driver side mirror are used to make automatic adjustments to a passenger side mirror without requiring the operator to make separate independent adjustment of the mirror. The automatic adjustment is determined using a measured horizontal angle of the driver side mirror along with distance data related to a position of an inboard edge of each of the exterior side mirrors based on a popular setting method, namely a Blindzone setting method (FIG. 1A). In the Blindzone setting method of FIG. 1A, a vehicle 9 has a left-hand side rearview mirror (L) and a right-hand side rearview mirror (R). The vehicle 9 also has an interior rearview mirror (I). If not obstructed, the interior rearview mirror overlaps coverage of the outside side rearview mirrors when the mirror is centered on a road. The field of view of the outside side rearview mirror is about half that of the interior rearview mirror. As such, shaded regions 9b in FIG. 1A are blindzones in which other vehicles 9c may be located and cannot be seen in either the interior rearview mirror or the driver's peripheral vision. As a result, it is still necessary to turn and look into the blindzones when changing lanes.
While the Blindzone method might be a more popular setting method, it is not a recommended method by experts unless the interior rearview mirror is obstructed, in which case, the method offers better coverage of the back of the vehicle. Instead, another method, namely a Blindzone/Glare Elimination (BGE) setting method (FIG. 1B), is recommended by experts to set the rearview mirrors of the rear vision system.
In the Blindzone/Glare Elimination setting method of FIG. 1B, the field of view of each outside side rearview mirror is turned outward by about fifteen degrees (15) from the blindzone setting. There are now four (4) mini blindzones 9b, but none is large enough to hide other vehicles 9c. With this setting method, it is no longer necessary to turn and look into the blindzones when changing lanes. All that is required is a glance at the outside side mirror to see if other vehicles 9b are there.
Therefore, it is desirable to provide a rear visions system having an automatic setting method that allows use of the Blindzone/Glare Elimination (BGE) setting method to adjust a rear vision system. It is also desirable to provide a rear vision system that synchronizes adjustment of the rearview mirrors. It is also desirable to provide a rear vision system having an automatic setting method detection and selection that allows use of either the Blindzone setting method or the Blindzone/Glare Elimination (BGE) setting method to adjust a rear vision system in a manner transparent to the driver. It is further desirable to provide a rear vision system having an automatic setting method that includes a position of a seat in adjustment of the rearview mirrors. Therefore, there is a need in the art to provide a rear vision system that meets these desires.